What is the diagnosis and treatment for Giant Cell (GCA) Temporal Arteritis?

From the Guidelines

Temporal arteritis, also known as giant cell arteritis, requires immediate treatment with high-dose corticosteroids, such as prednisone 40-60mg daily, to prevent vision loss and other complications, as recommended by the 2021 American College of Rheumatology/Vasculitis Foundation guideline 1.

Key Considerations

• The condition typically affects adults over 50, with symptoms including new-onset headache, scalp tenderness, jaw claudication, vision changes, and constitutional symptoms like fever and weight loss.
• The standard initial treatment should be started immediately upon suspicion of the diagnosis, even before confirmation with a temporal artery biopsy.
• After symptoms improve, typically within 2-4 weeks, the dose can be gradually tapered over 12-24 months.
• Adjunctive therapy with tocilizumab (162mg subcutaneously weekly or every other week) may be considered to reduce steroid requirements, as approved by the US Food and Drug Administration for the treatment of GCA 1.

Management and Prevention

• Patients should also take calcium (1200-1500mg daily) and vitamin D (800-1000 IU daily) supplements to prevent steroid-induced osteoporosis, and may need a bisphosphonate if on long-term steroids.
• Low-dose aspirin (81mg daily) is often recommended to reduce the risk of ischemic complications.
• Regular monitoring of symptoms, inflammatory markers (ESR and CRP), and steroid side effects is crucial.
• The 2021 American College of Rheumatology/Vasculitis Foundation guideline 1 and the 2018 update of the EULAR recommendations for the management of large vessel vasculitis 1 provide evidence-based recommendations for the evaluation and management of GCA.

Diagnosis and Treatment

• Diagnosis is based on clinical presentation, pathologic abnormalities on temporal artery biopsy, and/or evidence of large vessel involvement on vascular imaging 1.
• High-dose GC therapy (40–60 mg/day prednisone-equivalent) should be initiated immediately for induction of remission in active GCA or TAK, as recommended by the 2018 update of the EULAR recommendations for the management of large vessel vasculitis 1.
• Referral to an experienced centre for further work-up, including large-vessel imaging, is recommended for patients with suspected GCA or TAK 1.

From the FDA Drug Label

1. 2 Giant Cell Arteritis (GCA) ACTEMRA® (tocilizumab) is indicated for the treatment of giant cell arteritis (GCA) in adult patients.

Temporal Arteritis is another term for Giant Cell Arteritis (GCA).

• The FDA drug label for tocilizumab indicates that it is approved for the treatment of GCA in adult patients 2.
• This suggests that tocilizumab may be a suitable treatment option for temporal arteritis.

From the Research

Temporal Arteritis Treatment

• The primary treatment for temporal arteritis is corticosteroids, with the initial dose and duration of treatment varying depending on the severity of the disease and patient comorbidities 3.
• A study published in 1988 found that an initial dose of 35 mg prednisone daily was sufficient to control symptoms and signs in most patients, but flare-up rates were high, especially in the first 24 months of treatment 4.
• Another study published in 1997 compared the efficacy and adverse effects of different corticosteroid dose regimens in temporal arteritis, finding that a starting dose of 30-40 mg/d of prednisone was effective and less toxic than higher dose regimens 5.

Corticosteroid Dosage and Duration

• The choice of initial prednisone dosage takes into account the disease severity and comorbidities to reduce drug side effects 3.
• A gradual tapering of the steroid dose should occur over at least 1 year, with consideration of the use of steroid-sparing agents if iatrogenic steroid complications occur 6.
• Low-dose aspirin may benefit patients suffering from ischemic complications or with multiple cardiovascular risk factors, but randomized controlled trials are necessary to precise its benefit-to-risk ratio 3.

Diagnosis and Monitoring

• Temporal arteritis should be considered a medical emergency due to the seriousness of end-organ damage, particularly visual symptoms 6.
• The presence of a tender temporal artery mandates a temporal artery biopsy, and high-dose steroids should be begun the moment the diagnosis is considered 6.
• Careful monitoring of the response, both clinically and with serial inflammatory markers, is required 6.
• Elevated erythrocyte sedimentation rate is a common laboratory finding in temporal arteritis, and abnormalities on temporal artery biopsy are the gold standard for diagnosis 7.